Question 1165426
It's a two sample t-test
t=(x1-x2)/sqrt(s1^2/n1)+(s2^2/n2)

t is with df=28, and at the 95% level, the critical value is |t|>2.048

t=0 since the means are the same, and the numerator is 0, so there is no difference.

If the mean for the second were say 4.0
then t=(0.3)/sqrt (0.0091+0.0064)
=0.31/0.1246
=2.49, and that is a significant difference in longevity  based on the critical value.

Check to see if the means of each sample were different.